(1) influence 表示“影响”，主要指对行为、性格、观点等产生间接的或潜移默化的影响。通常为不可数名词，但有时可连用不定冠词。如:What you read influences your thinking.你读的东西对你的思想有影响。Television has a strong influence on people.电视对人有很大的影响。

influence可用作及物动词。如:It's clear that her painting has been influenced by Picasso.她的画显然受了毕加索的影响。

(2) effect可用作可数或不可数名词。用作可数名词时，常与介词on连用。have an effect on相当于affect。如:To affect a policy is to have an effect on it.影响一项政策就是对该政策具有一种影响。The news had no effect on her at all.=The news did not affect her at all.这条消息对她没有一点影响。

effect有时虽用作动词(及物),但不表示“影响”,而表示“实现”或“产生”等。如:He effected great changes in the company.他使公司发生了巨大的变化。